---
title: "Hallelujah by Jeff Buckley"
output:
  flexdashboard::flex_dashboard:
    orientation: columns
    vertical_layout: fill
    social: menu
    source_code: embed
    theme:
      version: 4
      bootswatch: sandstone
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE)

library(flexdashboard)
library(plotly)
library(rvest)
library(dplyr)
library(ggplot2)
library(stringr)
library(tidyr)
library(showtext)
library(gganimate)
library(forcats)
library(DT)

# function for scraping text from webpage
scrape_data <- function (x) {
  y <- read_html(x) %>%
    html_text()
  return(y)
}

# url of tab
tab_url <- "https://www.guitartabs.cc/tabs/j/jeff_buckley/hallelujah_tab_ver_7.html"

capo_from_url <- function(tab_url) {
  # scrape data from guitartabs.cc
  song_html <- scrape_data(tab_url)
  
  # extract tab section
  song_text <- sub('\\\tComments.*', "", sub('.*Artist:', "", song_html))
  # extract capo
  capo_text <- str_match_all(song_text, "Capo:*(.*?)\\s*\\\r")
  capo <- as.numeric(str_extract(capo_text,"\\(?[0-9,.]+\\)?"))
  
  return(capo)
}

songdf_from_url <- function(tab_url) {
  # scrape data from guitartabs.cc
  song <- scrape_data(tab_url)
  
  # extract tab section
  song_text <- sub('\\\tComments.*', "", sub('.*Artist:', "", song))
  
  # extract individual strings
  song_tab <- str_match_all(song_text, "\\\n\\|\\s*(.*?)\\s*\\|\\\r")
  
  #count of tab rows
  tab_count <- nrow(song_tab[[1]]) / 6
  # combine with notes and octave data
  song_df <- data.frame(tabs = song_tab[[1]][1:nrow(song_tab[[1]])],
                              notes = rep(c("E", "A", "D", "G", "B", "E"), tab_count),
                              string = rep(c("1", "2", "3", "4", "5", "6"), tab_count),
                              tab_row = (rep(c(seq(1:tab_count)), each = 6)),
                              octave_id = rep(c(2, 2, 3, 3, 3, 4), tab_count))
  
  # extract individual notes and calculate actual note played
  song_long <- song_df %>% 
    mutate(tab_raw = tabs,
           tabs = str_extract_all(song_df$tabs,"\\(?[0-9,.]+\\)?")) %>% 
    unnest(cols = tabs) %>%
    group_by(tab_row, string) %>%
    mutate(note_num = 1:n()) %>%
    mutate(tab_pos = as.list(gregexpr("\\(?[0-9,.]+\\)?", tab_raw))[[1]][note_num]) %>%
    left_join(guitar_strings, by = c("notes", "octave_id")) %>%
    mutate(pos_id = (tab_row * 1000) + tab_pos,
           tabs = as.numeric(tabs),
           id = id + tabs + capo) %>%
    select(-notes, -octave_id) %>%
    left_join(full_scale, by = "id")
  
  return(song_long)
}

# octave of notes
notes <- data.frame(notes = c("C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"))

# full potential range of guitar
full_scale <- data.frame(id = seq(1:(nrow(notes) * 6)),
                         notes = c(rep(notes$notes, 6)),
                         octave_id = c(rep(seq(1:6), each = nrow(notes)))
                         )

# standard tuning strings
guitar_strings <- data.frame(notes = c("E", "A", "D", "G", "B", "E"),
                             octave_id = c(2, 2, 3, 3, 3, 4)) %>% 
  left_join(full_scale, by = c("notes", "octave_id"))

bgcolor <- "#e6dacf"
fgcolor <- "#192530"
palette <- c("A" = "#90486c", 
             "A#" = "#6c3b4d", 
             "B" = "#d9b239", 
             "C" = "#ca7e6c", 
             "C#" = "#a74a4a", 
             "D" = "#d17826", 
             "D#" = "#a35712", 
             "E" = "#3d667e", 
             "F" = "#53a578", 
             "F#" = "#3b6c58", 
             "G" = "#e06846", 
             "G#" = "#c14333")

tab_url <- "https://www.guitartabs.cc/tabs/j/jeff_buckley/hallelujah_tab_ver_7.html"
capo <- capo_from_url(tab_url)
song_df <- songdf_from_url(tab_url)

```

Sidebar {.sidebar}
--------------------------------------------------------------------------------

```{r}
valueBox(nrow(song_df))
```


Column {data-width=650}
--------------------------------------------------------------------------------

```{r}
a <- song_df %>%
  mutate(string = factor(string, levels = c("6", "5", "4", "3", "2", "1"))) %>%
  select(pos_id, string, tabs, tab_row, notes) %>%
  mutate(tabs = as.numeric(gsub(0, NA, tabs))) %>%
  ggplot(aes(x = string, y = tabs)) +
  geom_point(aes(color = notes), size = 20, alpha = 0.65, shape = 1, stroke = 8) +
  geom_col(aes(y = 12, fill = notes), width = 0.06, alpha = 0.65) +
  transition_states(pos_id, transition_length = 2) +
  shadow_wake(wake_length = 0.03) +
  exit_fade() +
  #scale_y_continuous(breaks = seq(1:max(whole_song_long$tabs)), limits = c(0, 12)) +
  scale_y_reverse(breaks = seq(max(song_df$tabs):1), limits = c(12, 0)) +
  scale_color_manual(values = palette) +
  scale_fill_manual(values = palette) +
  theme_minimal() +
  labs(y = "FRET", x = "", color = "NOTE\n") +
  guides(size = "none", fill = "none", color = guide_legend(title.position="top", title.hjust = 0.5)) +
  theme(legend.position = "right",
        text = element_text(family = "Red Hat Mono", size = 25, color = fgcolor),
        plot.background = element_rect(color = bgcolor, fill = bgcolor),
        panel.background = element_rect(color = bgcolor, fill = bgcolor),
        axis.title.y = element_text(face = "bold", size = 20, color = "#6c3b4d", hjust = 0.5),
        plot.title = element_text(hjust = 0.5, size = 40),
        panel.grid.major.x = element_line(size = 4.5, color = "#f5f1ed"),
        panel.grid.major.y = element_line(size = 1.5, color = "#8a6d51"),
        panel.grid.minor.y = element_blank(),
        legend.key.height = unit(100, "pt"),
        plot.subtitle = element_text(hjust = 0.5, size = 30),
        legend.text = element_text(size = 30),
        legend.title = element_text(face = "bold", size = 20, color = "#6c3b4d", hjust = 0.5))

# save animation
animate(a, height = 1800, width = 800, fps = 6, duration = 60)
anim_save("../outputs/img.gif")
```

![](../outputs/img.gif)